An engine mount of the above type is found in German Offenlegungsschrift DE-OS34 01 662. This prior art mount is a hydraulic engine mount for supporting the axles of heavy motor vehicles. The engine mount is comprised of two rubber-metal mounts that are nested one inside the other, with the inner rubber-metal mount being fitted with a hydraulic damping device. The damping device is comprised of two hydraulic chambers, one of them being positioned above and the other below the elastomer element. The two rubber-metal mounts and the hydraulic device constitute a unified assembly, so that the engine mount cannot be alternatively utilized with or without the hydraulic damping device
German Offenlegungsschrift DE-OS 36 16 043 discloses another related engine mount but in which both hydraulic chambers of the hydraulic damping device are fitted annularly around the engine mount. The disadvantage of this arrangement is that the volume of the two hydraulic chambers must be kept relatively small and, as a result, the damping effectiveness of this prior art engine mount is relatively limited. Furthermore, the hydraulic damping device in this engine mount is also an integral part of the engine mount assembly so that this engine mount, too, cannot be used alternatively with or without the hydraulic damping device. However, to have this option available is very important since the comfort requirements vary with different types of vehicles.